Centrifugal pump with dual impeller



1940" o.- JACOBSEN 2,219,390

CENTRIFUGAL PUMP WITH-DUAL IMPELLER Filed Sept. 12, 1938 2 Sheets-Sheet 2 7 INVENTOQ.

\ 0mm dncowzu B JW1-$M r flrrama Patented Oct. 29, 1940 UNITED. STATES PATENT; OFFICE CEN'rmI-UGAL PUMP wrrn DUAL N memes g Oystein J acobsen, Montgomery County, Ohio, as-

signor to The Durlron Company, Inc., Dayton, Ohio, a corporation of'New York Application September 12, 1938, Serial No. 229,470 V 3' Claims. (Cl. 103-115) I This invention relates to centrifugal pumps, Figure2 is a central cross section taken along 'and if particular, to such pumps forpumping the line 2--2 in Figurel.

corrosive fluids.

One object of this invention is to provide a m arrangement 5 centrifugal pump having means for preventing Ingeneral, the centrifugal p p of h s ,in- 5 'the flow of corrosive fluid along the drive shaft vention s i r't e u p o co osive d through t packing thereeh fluids, which in prior pumps have leaked along Another object is to provide a centrifugal the a p st he ha t p ck v e pump having an impeller mounted on a shaft hereby created grea damage, t P t 10 supported withi a casing, th 11 having therebeyond. The present invention provides "a 10 dual pumping function, one consisting hollow impeller with the vanes thereof dividing p i th m body of fluid fro t pump the interior of the impeller into two sets of vane intake chamber and the other consisting of b s- The fl Ui V e Ch mbers 00mm m t leakage -flu1d from t chamber municates directly with the intake chamber of adjacent the packing so as to prevent the leakage the pump, Whereas the Second et Of V e ehem- 15 of 1 fluid alongthe m I bers'communieates directly with a chamber in Another object is to provide a centrifugal .commurflcatlen w h e P s a t packin pump having an impeller with dual sets of vanes, The seeond Set 01 Vane chambers, hOWeVel. 18

' one set of vanes working on the centrifugal princonnected the first Set y means of e ct d g ciple to pump one portion of fluid, the other set P These Ports S l a let action wlthin'the 20 of vanes working upon the Jet principlefor second set of vane chambers, thereby providing pumping fluid from another portion of the 8 Suction in the letter and a Second D p eifect. 'I'heinteriors oi the vane chambers are casing. Another object is to provide a centrifugal preferably made todiverge outwardly with an T :5 pump having a hollow impeller and vanes inapproximately Venturi configuration. closing separate chambers within the impeller, Cmtmction' one set of vane chambers opening into the pump intake chamber, the other set of vane chambers Referrinfl t e drawings in detail, Figure 1 opening nt chamber adjacent t pump shows a pump constructed according to the prinshaft packing. v ciples of the invention, and consisting of a cas- Another object is to provide a centrifugal mg having an en p ate Secured thereto pump, as set forth in the. preceding paragraph, y t e clamping ring IL with e peeking wherein one set of vane chambers operates upon e w no ts I d" e p g ring the centrifugal principle and the other set upon e d p t II a d th cas in ethe jet principle, preferably set up by meansof ment i e P p pp The 8 35 ports interconnecting the two sets of vane (F ure 2) is of volute shap heVinB i har e chambers. port It terminating in an enlarged outlet end Another object is to provide a centrifugal l'i eng 'ged by a clamping ring l8 for the securpump having a casing with an intake chamber ing thereto of a dischargeconduit. Similarly,

40 and a hollow impeller mounted on a shaft, and the end plate II is provided with an intake ex- 40 having vanes separating the interior of the -imtension IS with an intake chamber 20 containing peller into two sets'of vane chambers, the vane vanes 2| for preventing the swirling of the fluid chambers of oneset being directly connected to entering the pump. The outer end "of the inthe pump intake chamber, the other set 01' vane take extension I9 is enlarged, and engaged by a chambers being connected to a chamber comclamping ring 23 for thepurpose of securing 45 mimiceting w e pu p h ft packin and thereto an intake conduit. The lower end of I.

connected to the first set of vane chambers by the casing III is provided with a drainage extenmeans of restricted ports setting up a jet action sion 24 having a drainage port 2!, closed by a to provide a pumping eflect within the second plate 28 held in position by the U-bolt 21.

set of vane chambers. .The casing ID, or volute as it is also called by 50 In the drawings: hydraulic engineers, is provided with a stufllng Figure 1 is a central longitudinal section box extension 28 containing a packing 2! surthrough a preferred embodiment of the pump rounding the pump drive shaft 30. The latter is of this invention, taken along the broken line provided with a'reduce'd diameter portion II hav- 1 l-i in Figure 2. i ng a hub thereon, connected to and support- .55 I

side plates 33 and 34 are spirally directed vanes s 36. These vanes divide the interior of the impeller into alternately arranged vane chambers 3'! and 38, respectively. The vane chambers 31 (Figure 1) at their inner ends open into the intake passageways 39 communicating with the pump intake chamber 20, whereas the vane chambers 38 open through the passageways ll into the leakage chamber ll on the opposite side of the hub 32 from the pump intake chamber 2|.

Restricted ports 42 interconnect the vane cham-' bers 38 and the impeller -hub chamber 43 (Figure 1). The surfaces 44 and 45 of the hub chamber 43 and pump intake chamber 2| are curved in an axial direction to take care of the vena contracts. efl'ect and increase the emciency of the pump. The impeller 3| is separated from the adjacent inner walls of the casing II and end plate H by spaces or gaps l and 41, respectively, these gaps being necessary to permit free rotation of the impeller 3!.

Operation In the operationof the pump of this invention the rotation of the shaft ll causes the vanes ll, by their centrifugal action, to set up a suction in their intake passages 8. leading into the hub chamber 48, thereby pumping the main body of the fluid from the pump intake chamber 2| outwardly through the vane chambers 31, and into the volute chamber ll, thence out through the discharge passageway it, into the discharge conduit. At the same time the jet effect of the ports 4: sets up a suction and pumping action within the vane chambers ll, thereby pumping fluid through the latter from the leakage chamber ll, through the passageways 4|. The leakage fluid thus passes outwardly through the vane chain beta 38 and is likewise discharged into the volute chamber Cl, and continues through the discharge passageway il, into the discharge conduit.

In this manner the vane chambers 31 are caused to pump the main body of the fluid from the pump intake chamber 20 by means of a centrifugal action, whereas the vane chambers ll pump the leakage fluid from the leakage chamber 4| outwardly by means of the jet action arising from the eirect of the ports 42. The leakage fluid in the leakage chamber ll, which would 2,a19,soo

otherwise tend to work its way along the shaft 30 and through the packing ",into the other parts of the mechanism, is thus prevented from doing so, and is constantly being pumped out of the pump along with the main body of the fluid. It will be understood, of course, that the various parts of the pump are constructed of corrosionresisting materials for resisting the corroding eflfects of the acids and other fluids handled by the pump.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desire to secure by letters Patent is:

1; In a centrifugal pump, a casing, a rotary impeller in said casing, and hollow vahes in, said impeller forming one set of chambers, the spaces between the vanes forming another set of chambers, said sets of chambers communicating respectively with the opposite sides of said impeller, said sets of chambers having interconnecting ports 'near the inner ends of said hollow vanes.

2. In a centrifugal pump, a casing, a rotary impeller in said casing, and hollow vanes in said impeller forming one set of chambers, the spaces between the vanes forming another set or chambers, said sets of chambers communicating respectively with the opposite sides of said impeller, said sets of chambers having interconnected ports of restricted diameters near the inner ends of said hollow vanes.

3. In a centrifugal pump, a casing, a shaft rotatably supported at one side of said casing and terminating within said casing, a packing disposed between said shaft and said casing, an impeller hub on said shaft, a pair of side plates spaced by hollow vanes and joined to said hub. said hollow vanes forming with said side plates one set of chambers, and the spaces between said vanes and, said side plates forming another set of chambers, said sets of chambers opening re-' spectively into spaces on opposite sides of said hub and having near the inner ends of said hollow vanes interconnecting ports which have a restricted diameter and extend through a portion of said hub.

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